Dry shaver with a self adjusting shear plate and rotary cutter



Aug. 25, 1959 G. STARRE ETAL DRY SHAVER WITH A SELF ADJUSTING SHEARPLATE AND ROTARY CUTTER Filed Dec. 27, 1956 INVENTOR DRY SHAVER WITH ASELF ADJUSTING PLATE AND ROTARY CU'ITER Gerrit Starre and Eppe Bakker,Drachten, Netherlands, assignors, by mesne assignments, to NorthAmerican Philips Company, Inc., New York, N.Y., a corporation ofDelaware Application December 27, 1956, Serial No. 630,824

Claims priority, application Netherlands January 17, 1956 3 Claims. (CI.30-43) This invention relates to improvements in or relating todry-shaving apparatus having a shear plate adapted to take up aninclined position with respect to the axis of the apparatus and a rotarycutting member co-operating with said plate.

In dry-shaving apparatus having a shear plate adapted to take up aninclined position with respect to the axis of United States Patentsponding cross-section is arranged with a certain amount of play. By aspring surrounding the driving element the cutting member is urged tothe shear plate.

It has been found that the above known movable conmotion between the'cutting member and the driving element is not always satisfactory.Frequently, this relative movement results in that during shaving thecutting member performs a rocking movement over the shear plate, so thatnot all the hairs extending through the apertures of the shear plate arecut off. Thisrocking movement also resultsin uneyenwear of the shearplate and .the cutting member, so that after prolonged use the cuttingedges cannot accurately engage the shear plate.

The causes of this rocking movement have remained obscure a long time inspite of prolonged and intensive research. However, it has now beenfound that the known movable connection between the cutting member andthe driving element prevents the cutting member from invariablyadjusting itself accurately to the shear plate.

It is an object of the present invention to obviate this disadvantage.

According to the invention, this movable connection consists of a singlethin spindle, the straight middle part of which is journalled in agroove formed in the end of the driving shaft, the straight ends of thisspindle lying in a plane passing through the middle part so as to extendat right angles to this middle part and being journalled in the cuttingmember, while the parts connecting the straight ends to the middle partare spaced away from the driving shaft.

Thus, a simple highly movable connection is obtained which enables thecutting member to take up an inclined position with respect to the axisof the dry-shaving apparatus equally well in all directions, only aminimum friction having to be overcome. The fact that the connectingparts of the thin spindle are spaced away from the driving shaft ensuresthat they are not prevented by this shaft from following a change inposition of the cutting member. In addition, the shear plate is now aslittle as possible prevented by the cutting member from taking up aposition which conforms withthe shape of the skin to which the shearplate is pressed. Even when the shear plate occupies an inclinedposition, the cutting member is completely free to adjust itself to theshear is capable of axial movement, the cutting member is rigidlyjournalled in the axial direction, so that the shear plate is supportedby the cutting member. Thus, by means of the pressure of the apparatuson the skin,

the user can determine the pressure between the shear plate and thecutting member, which latter'pressure must be greater for a personhaving a heavy beard than for a person having a light beard in order toensure the optimum shaving efficiency. This effect can also be achievedby means of a shaving head according to a prior suggestion, in which thecutting member is rigidly journalled and the shear plate is displaceableonly in a direction parallel to itself. In this proposed construction,theshear plate must be guided witha high degree of accuracy. Even withsmall deviations, the cutting member is likely. to catch in the shearplate and to rip it open.

According to the invention, the surface area'of the shear plate can beincreased, since this plate is supported by the cutting member, so thatthe plate is less likely to sag or even break. It is also possible toarrange a number of plates concentrically with respect to one another,each plate being freeto adjust itself with respect to the remainingplates. 1

In order to prevent the cutting member from performing axial vibrations,bywhich the cutting member might damage the shear plate, it is necessaryin view of the rotary movement of the cutting member that the thinspindle isaccurately centered with respect tothe cutting member.According to afurther feature-of the invention, the cutting member isprovided with an annular thickened portion having grooves formed in it;in which the straight ends of the thin spindle are journalled, 'aclosingcover being clamped over-the annular thickened portion.

This ensures a very effective and cheap centering of the cutting member,the shear plate being prevented from vibrating.

In order that the invention may readily be carried out, one embodimentof a dry-shaving apparatus in accordance with the invention will now bedescribed, by way of example, with reference to the accompanyingdiagrammatic drawings, in which:

Fig. 1 is a cross-sectional view of part of the dryshaving apparatus inaccordance with the invention,

Fig. 2 is a bottom plan-view of the cutting member and the thin spindle,the closing cover being removed, and

Fig. 3 shows a structural detail of the shear plate and the apparatus.

In the figures, corresponding parts are designated by like referencenumerals.

A shear plate 1 is arranged in the apparatus between annular stops 2 and3 so as to be freely adjustable. Along its circumference, the stop 3 isprovided with at least one rib 4 arranged in recesses 5 in the rim 6 ofthe shear plate 1, so that this shear plate is prevented from rotatingabout its axis. Fig. 3 discloses two ribs 4 on opposite sides of therazor casing and arranged in recesses 5. Thus, the shear plate 1 isprevented from rotational move ment about its axis by means of ribs 4 inrecesses 5. However, limited axial movement of the shear plate 1 ispermitted between the stops 2 and 3.

Below the shear plate 1 provision is made in the usual manner of acutting member 7 which is coupled to a driving shaft 8 by means of athin spindle 9. The straight middle portion 10 of this spindle isjournalled in a groove 11 of the driving shaft 8. Straight ends 12, 13lie in the plane of the straight middle portion so as to be at rightangles thereto. The ends 12 and 13 are journalled in grooves 14, 15 ofan annular thickened portion 16 of the cutting member 7. 'Between theends 12, 13. and the straight middle portion 10 of the "thinspindle 9provision is made of connecting parts 17, "18 at some distance from thedriving shaft 8, so that the thin spindle 9 is sufliciently free to moverelatively to the driving shaft 8.

The driving shaft 8 is rigidly journalled in the axial direction, sothat the shear plate 1 is supported by the cutting member 7.

What is claimed is:

1. A dry shaver comprising a shear plate adapted to be positionedangularly relative to the axis of said shaver, a rotary cutting memberco-acting with said shear plate and adjustable therewith, a drivingshaft having a groove in one end thereof, means connecting said rotarycutting member to said driving shaft, said means including a sinuousspindle provided with a linear middle portion having part thereof insaid groove, and straight end portions extending in the same plane assaid middle portion and substantially at right angles thereto, said endportions'secured to said cutting member, and parts connecting said endportions to said middle portion spaced from and movable, a rotarycutting member co-acting with said shear plate, means preventing saidshear plate from rotational movement but permitting limited axialmovement thereof, means rigidly journalling said cutting mem- .4 ber inthe axial direction whereby said shear plate is supported by saidcutting member, 'a driving shaft havinga groove in one end thereof,means connecting said rotary cutting member to said driving shaft, saidlast mentioned means including a sinuous spindle provided with a linearmiddle portion'having part thereof in said groove, and straight endportions extending in the same plane as said middle portion andsubstantially at right angles thereto, said end portions secured to saidcutting member, and parts'connectingxsaid BlldjPOItlOll to :said middleportionspaced from said'driving shaft.

3. A dry shaver comprising a shear plate adapted to bepositionedangularly. relative to the axis of said shaver and movable, arotary cutting member co-acting with said shear plate, meansrigidlyjournalling said cutting member in the axial'direction wherebysaid shear plate is supported by s'aidcutting member, a driving shafthaving a groove in one end thereof, means connecting said rotary cuttingmember to said driving shaft, said last mentioned means including asinuous spindle provided with a linear middle portion having partthereof in said groove, and straight end portions extending in the sameplane as said middle portion and substantially at right angles thereto,said end portions secured to said cutting member, partsconnecting saidend portion to said middle portion spaced from said driving shaft, saidcutting member having an annular thickened portion with slots :therein,said straight end portions of said sinuous spindle in said slots, and aclosing cover affixed to said annular thickened portion.

References Cited inthe file of this patent UNITED STATES PATENTS2,119,284 Meyer May 31, 1938 2,279,682 'Jackson .Apr. 14,1942 2,280,052Bahr Apr. .21, 1942 2,341,833 Volz Feb. 15, 1944 2,677,884 Richard May11, 1954 2,716,278 Thompson Aug. 30, 1955 FOREIGN PATENTS 974,147 FranceSept. 27, 1950 491,339 Italy 'Mar. 4, 1954

